Almost every country in the world has legislation that prohibits physician-assisted suicide. The UK Parliament voted overwhelmingly to maintain its prohibition of the practice in 2015 (330 to 118), but the law has been challenged in recent cases (Conway and Nicklinson) under the Human Rights Act. Many legal scholars and human rights lawyers contend that legislatures do not have legitimate power to make the final decision on such a question. That power belongs to courts, they argue, because the question is one of constitutional or human rights, and thus a legal rather than a political question. The  same argument is applied to many other issues that pervade our political life and touch on our most basic interests and values. Courts around the world are now commonly asked to settle issues regarding data privacy, financing of election campaigns, voting rights, anti-terrorism measures, marriage, abortion, surrogacy, immigration, and many other matters of deep moral and political controversy. These issues involve questions of human or constitutional rights, it is said, and such rights ‘not up for a vote’.

My book Constitutional Rights and Constitutional Design: Moral and Empirical Reasoning in Judicial Review argues that courts lack the institutional capacities needed to make final resolutions on these kinds of issues. The power to strike down legislation because it violates abstract moral rights (such as the right to equality, privacy, or free speech) invites judges to engage in broad moral and empirical reasoning. Judges now commonly review empirical research to assess whether a law will effectively achieve its aim, and at what cost to other interests, citing studies and statistical information from disciplines such as psychology, sociology, and medicine, and an array of non-legal sources. This empirical reasoning proceeds alongside moral reasoning, with judges employing terms such as liberty, autonomy, and human dignity, determining what those values require in concrete circumstances. My book argues that, no matter how well trained and educated judges are, and no matter how carefully they are selected for office, the institutional setting of a court is lacking in basic capacities for moral and empirical reasoning. A legislature is the only institution designed to have the competence for deliberating on the full range of moral issues at stake and for assessing the complex information involved in the kinds of cases that are now increasingly subjected to constitutional adjudication.

Consider the case of Carter v Canada (2012), where the claimants argued that Canada’s prohibition on assisted suicide violated their constitutional rights to life and liberty. The trial, conducted by Justice Lynn Smith, a trial court judge in British Columbia, lasted several weeks, most of which was devoted to testimony from medical doctors, scientists, and ethicists. The evidence included 36 binders of written submissions and over 100 affidavits. It touched on many disputed questions of ethics—such as whether it is ever morally permissible to intend to cause death—and of empirical fact. A key factual issue was whether permitting assisted suicide is likely to lead to pressure on the aged and vulnerable to end their lives. Smith found that legalisation is not likely to lead to undue pressure (contrary to findings made by Parliament in Canada and the UK and by many other national legislatures) and proceeded to hold the law unconstitutional. The Canadian Supreme Court affirmed Smith’s decision in 2015, rubber-stamping her empirical findings—despite the fact that in the two previous decades the Canadian Parliament had debated several times whether to amend the law on assisted suicide. At least nine bills proposing to legalise the practice failed to pass, including one in 2010 that Parliament rejected by a vote of 228 to 59.

Why should such a momentous decision—with all its attendant moral controversy and factual complexity—come down to the decision of a single judge (in the first instance) or a panel of judges at a higher level? Some critics of judicial review have vigorously argued that entrusting such decisions to courts violates the fundamental democratic principle of equal participation in government. No less vigorously, defenders of judicial review have contended that it is necessary to ensure the survival of a healthy form of democracy that protects the rights of all, including minorities. My book focuses on a different question: whether or not courts and judges have the institutional capacity needed to settle the kinds of morally and politically controversial issues that arise in constitutional rights cases.

The first part of the book (chapters 1 to 3) shows that constitutional and human rights serve primarily to invoke balancing and proportionality tests. Because they are formulated in vague and abstract moral language, these rights provide little or no direction for deciding individual cases. They are almost always treated as defeasible, as interests that can be legitimately infringed. Courts do not so much define the meaning of rights as determine how far they can be interfered with—a determination made with recourse to the kind of moral and empirical reasoning seen in Carter, applied through a proportionality test. Even the originalist approach to constitutional interpretation promoted by Justice Scalia and other US judges often ends in a balancing test and use of empirical evidence. Ronald Dworkin urged us to conceive of rights as ‘trumps’, but I argue that his theory of rights fails to avoid the problems of balancing tests.

The second part of the book (chapters 4 to 6) consists in comparative analysis of the institutional capacities of courts and legislatures to engage in moral and empirical reasoning. While courts are well-designed for fact-finding regarding the who, what, and why of an individual case, they have very weak capacities for finding general empirical facts about society. In constitutional rights cases they rely on empirical research submitted by parties as well as research undertaken on their own initiative, often in haphazard fashion, sometimes using internet searches and citing dubious sources (even Wikipedia). Do violent video games lead to violence? What is the effect of restricting tobacco advertisement on youth smoking rates? With increasing boldness, judges plow through the research in search of answers. Close analysis of cases, however, shows widespread misunderstanding of social science methodology and frequent misuse of studies. Legislatures have vastly superior capacities to acquire and assess empirical research and to engage in open-ended deliberation on moral questions. Whether they exercise this capacity well is another question, but the most common argument for mistrusting legislatures—their  ‘majoritarian’ character—is often exaggerated. As Cass Sunstein observed regarding developments in the US since Brown v Board of Education (1954): ‘Fifty years later, Brown does seem increasingly anomalous. Before the Warren Court, the justices were almost never a force for social reform, and they have rarely assumed that role in the past two decades. Most of the time, the judiciary has been an obstacle to racial equality’ (emphasis added).

The final chapter of the book (chapter 7) discusses ways in which constitutional courts could be reformed in order to overcome their lack of institutional capacities for engaging in moral and empirical reasoning. Historical analysis shows that neither common law supreme courts (on the American model) nor constitutional courts (on Hans Kelsen’s model) were intentionally designed as institutions with the purpose of settling questions of moral and political controversy through moral and empirical reasoning. Taking the perspective of a constitutional framer who is contemplating a court to resolve questions about constitutional rights, I argue that the Kelsenian model is generally superior to the American model in providing for review that is centralized and abstract, with a remedial system more fit for purpose. Both models could be improved by adding a research service to acquire and assess general facts about society. Moreover, lay justices (as used in the French Constitutional Council) could help to avoid the problem of correlated biases. Since constitutional rights cases are decided mainly by applying balancing tests, participation need not be restricted to graduates of elite law schools. The end result of adopting all these features would be to create a quasi-legislative body different from an ordinary court. While individual features could be adopted to improve existing systems of review, the chapter’s main purpose is not a comprehensive discussion of such reform but to provide further illustration of the arguments about comparative institutional capacity made in chapters 4 to 6, highlighting the deficiencies of current constitutional and supreme courts. A constitutional framer might well conclude that the best approach is one of legislative supremacy—where the legislature has power to make final decisions about the kinds of issues now routinely made the subject of constitutional rights cases.

Paul Yowell is a fellow of Oriel College and associate professor in the faculty of law. Previously, he was a lecturer at New College. He did his postgraduate studies at Oxford (DPhil, MPhil, BCL), having previously practiced law and studied in the US (JD, BA, Baylor University). He is also on the adjunct faculty of the University of Notre Dame. He is the author of Constitutional Rights and Constitutional Design: Moral and Empirical Reasoning in Judicial Review, co-author of Legislated Rights: Securing Human Rights Through Legislation and one of the editors of Lord Sumption and the Limits of the Law. He researches broadly in public law and legal theory, with particular interest in the separation of powers, Constitutional theory, comparative constitutional law, and human rights.